mirror of
https://git.anonymousland.org/anonymousland/synapse-product.git
synced 2024-12-12 04:34:18 -05:00
33b40d0a25
popitem removes the *most recent* item by default [1]. We want the oldest. Fixes #3524 [1]: https://docs.python.org/2/library/collections.html#collections.OrderedDict.popitem
226 lines
7.5 KiB
Python
226 lines
7.5 KiB
Python
# -*- coding: utf-8 -*-
|
|
# Copyright 2015, 2016 OpenMarket Ltd
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
|
# you may not use this file except in compliance with the License.
|
|
# You may obtain a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
# See the License for the specific language governing permissions and
|
|
# limitations under the License.
|
|
|
|
import collections
|
|
import contextlib
|
|
import logging
|
|
|
|
from twisted.internet import defer
|
|
|
|
from synapse.api.errors import LimitExceededError
|
|
from synapse.util.logcontext import (
|
|
PreserveLoggingContext,
|
|
make_deferred_yieldable,
|
|
run_in_background,
|
|
)
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
class FederationRateLimiter(object):
|
|
def __init__(self, clock, window_size, sleep_limit, sleep_msec,
|
|
reject_limit, concurrent_requests):
|
|
"""
|
|
Args:
|
|
clock (Clock)
|
|
window_size (int): The window size in milliseconds.
|
|
sleep_limit (int): The number of requests received in the last
|
|
`window_size` milliseconds before we artificially start
|
|
delaying processing of requests.
|
|
sleep_msec (int): The number of milliseconds to delay processing
|
|
of incoming requests by.
|
|
reject_limit (int): The maximum number of requests that are can be
|
|
queued for processing before we start rejecting requests with
|
|
a 429 Too Many Requests response.
|
|
concurrent_requests (int): The number of concurrent requests to
|
|
process.
|
|
"""
|
|
self.clock = clock
|
|
|
|
self.window_size = window_size
|
|
self.sleep_limit = sleep_limit
|
|
self.sleep_msec = sleep_msec
|
|
self.reject_limit = reject_limit
|
|
self.concurrent_requests = concurrent_requests
|
|
|
|
self.ratelimiters = {}
|
|
|
|
def ratelimit(self, host):
|
|
"""Used to ratelimit an incoming request from given host
|
|
|
|
Example usage:
|
|
|
|
with rate_limiter.ratelimit(origin) as wait_deferred:
|
|
yield wait_deferred
|
|
# Handle request ...
|
|
|
|
Args:
|
|
host (str): Origin of incoming request.
|
|
|
|
Returns:
|
|
_PerHostRatelimiter
|
|
"""
|
|
return self.ratelimiters.setdefault(
|
|
host,
|
|
_PerHostRatelimiter(
|
|
clock=self.clock,
|
|
window_size=self.window_size,
|
|
sleep_limit=self.sleep_limit,
|
|
sleep_msec=self.sleep_msec,
|
|
reject_limit=self.reject_limit,
|
|
concurrent_requests=self.concurrent_requests,
|
|
)
|
|
).ratelimit()
|
|
|
|
|
|
class _PerHostRatelimiter(object):
|
|
def __init__(self, clock, window_size, sleep_limit, sleep_msec,
|
|
reject_limit, concurrent_requests):
|
|
self.clock = clock
|
|
|
|
self.window_size = window_size
|
|
self.sleep_limit = sleep_limit
|
|
self.sleep_sec = sleep_msec / 1000.0
|
|
self.reject_limit = reject_limit
|
|
self.concurrent_requests = concurrent_requests
|
|
|
|
# request_id objects for requests which have been slept
|
|
self.sleeping_requests = set()
|
|
|
|
# map from request_id object to Deferred for requests which are ready
|
|
# for processing but have been queued
|
|
self.ready_request_queue = collections.OrderedDict()
|
|
|
|
# request id objects for requests which are in progress
|
|
self.current_processing = set()
|
|
|
|
# times at which we have recently (within the last window_size ms)
|
|
# received requests.
|
|
self.request_times = []
|
|
|
|
@contextlib.contextmanager
|
|
def ratelimit(self):
|
|
# `contextlib.contextmanager` takes a generator and turns it into a
|
|
# context manager. The generator should only yield once with a value
|
|
# to be returned by manager.
|
|
# Exceptions will be reraised at the yield.
|
|
|
|
request_id = object()
|
|
ret = self._on_enter(request_id)
|
|
try:
|
|
yield ret
|
|
finally:
|
|
self._on_exit(request_id)
|
|
|
|
def _on_enter(self, request_id):
|
|
time_now = self.clock.time_msec()
|
|
|
|
# remove any entries from request_times which aren't within the window
|
|
self.request_times[:] = [
|
|
r for r in self.request_times
|
|
if time_now - r < self.window_size
|
|
]
|
|
|
|
# reject the request if we already have too many queued up (either
|
|
# sleeping or in the ready queue).
|
|
queue_size = len(self.ready_request_queue) + len(self.sleeping_requests)
|
|
if queue_size > self.reject_limit:
|
|
raise LimitExceededError(
|
|
retry_after_ms=int(
|
|
self.window_size / self.sleep_limit
|
|
),
|
|
)
|
|
|
|
self.request_times.append(time_now)
|
|
|
|
def queue_request():
|
|
if len(self.current_processing) > self.concurrent_requests:
|
|
queue_defer = defer.Deferred()
|
|
self.ready_request_queue[request_id] = queue_defer
|
|
logger.info(
|
|
"Ratelimiter: queueing request (queue now %i items)",
|
|
len(self.ready_request_queue),
|
|
)
|
|
|
|
return queue_defer
|
|
else:
|
|
return defer.succeed(None)
|
|
|
|
logger.debug(
|
|
"Ratelimit [%s]: len(self.request_times)=%d",
|
|
id(request_id), len(self.request_times),
|
|
)
|
|
|
|
if len(self.request_times) > self.sleep_limit:
|
|
logger.debug(
|
|
"Ratelimiter: sleeping request for %f sec", self.sleep_sec,
|
|
)
|
|
ret_defer = run_in_background(self.clock.sleep, self.sleep_sec)
|
|
|
|
self.sleeping_requests.add(request_id)
|
|
|
|
def on_wait_finished(_):
|
|
logger.debug(
|
|
"Ratelimit [%s]: Finished sleeping",
|
|
id(request_id),
|
|
)
|
|
self.sleeping_requests.discard(request_id)
|
|
queue_defer = queue_request()
|
|
return queue_defer
|
|
|
|
ret_defer.addBoth(on_wait_finished)
|
|
else:
|
|
ret_defer = queue_request()
|
|
|
|
def on_start(r):
|
|
logger.debug(
|
|
"Ratelimit [%s]: Processing req",
|
|
id(request_id),
|
|
)
|
|
self.current_processing.add(request_id)
|
|
return r
|
|
|
|
def on_err(r):
|
|
# XXX: why is this necessary? this is called before we start
|
|
# processing the request so why would the request be in
|
|
# current_processing?
|
|
self.current_processing.discard(request_id)
|
|
return r
|
|
|
|
def on_both(r):
|
|
# Ensure that we've properly cleaned up.
|
|
self.sleeping_requests.discard(request_id)
|
|
self.ready_request_queue.pop(request_id, None)
|
|
return r
|
|
|
|
ret_defer.addCallbacks(on_start, on_err)
|
|
ret_defer.addBoth(on_both)
|
|
return make_deferred_yieldable(ret_defer)
|
|
|
|
def _on_exit(self, request_id):
|
|
logger.debug(
|
|
"Ratelimit [%s]: Processed req",
|
|
id(request_id),
|
|
)
|
|
self.current_processing.discard(request_id)
|
|
try:
|
|
# start processing the next item on the queue.
|
|
_, deferred = self.ready_request_queue.popitem(last=False)
|
|
|
|
with PreserveLoggingContext():
|
|
deferred.callback(None)
|
|
except KeyError:
|
|
pass
|